Right here's the deal - just called o2 now.
I asked the operator if io2 would charge me for changing over the VPN to mobile.o2.co.uk. She spoke to her manager who advised not to change the VPN over as it will charge me.
Earlier on this morning, o2 operators were telling people to change the VPN over and they would be refunded for short term effects. This is now not the case and she has warned that any VPN change usage from a few hours ago will not be refunded. She also told me that they were advising against the change to mobile.o2.co.uk because the change over and rush of demand was actually making the situation worsen and the problem longer to fix.
Don't know what anyone makes of that but her manager was strict on the fact that there would be no refunds as the problem should be fixed this afternoon, in a few hours time.
Just to let you all know!
Thanks for the info.